New owner of a (2008) 1.8 Ford focus TDCI. Are there any upgrades worth doing that I could DIY. I was thinking of putting in a cold air intake. Is this a bad idea. What is a good idea....

8 minutes ago, Adware said:

. I was thinking of putting in a cold air intake

Why ?

Hi Adam. A cold air intake isn't a bad idea. When I had a mk3 focus 1.6 diesel I fitted the K&N ST type airbox. It had a removable part which increased intake noise. That was fun lol but I got sick of that. However the K&N box did improve performance a little. I've still got that box as it happens (must get round to selling it).

You could look up also bolt on tuning boxes. There are a few threads on them on this forum but they hark back around 2018 or before. Some boxes are great most are not. I can't remember which However but technology has moved on tons since then so some research by you needs to be done. Tuning boxes plug into the fuel rail and MAF if I remember right but OEM adapter plugs are used so no soldering etc needs to be done.

Anything that doesn't cost much provides an equivalent increase in performance - perception of improvements comes from the placebo effect of having spent money on it and it making more noise!

And thinking of performance - how often do you really use full throttle?

18 hours ago, agraham said:

Anything that doesn't cost much provides an equivalent increase in performance - perception of improvements comes from the placebo effect

The OP just needs a set of "go faster stripes" 🤣

On 9/23/2023 at 3:52 PM, Adware said:

New owner of a (2008) 1.8 Ford focus TDCI. Are there any upgrades worth doing that I could DIY. I was thinking of putting in a cold air intake. Is this a bad idea. What is a good idea....

Pipercross Air Filter, don't waste your money on induction kits on a Diesel. K&Ns aren't as good as Pipercross

Cetane boosting additive for fuel

Remap, not a tuning box

Dave. I don't know what your experience is with tuning diesels. I've done both remap and tuning boxes. Tuning boxes wipe the floor with a remap is my experience and on 7 diesels I've had. Tuning boxes, the good proper ones, are simple to fit. Cost a fraction too. Can also be disconnected within 2 minutes. No remap can from start to finish.  As for pipercross. Great on Minis of old and not much else. K&N are ultra reputable. Tried tested and adored.

40 minutes ago, tazzman600 said:

Dave. I don't know what your experience is with tuning diesels. I've done both remap and tuning boxes. Tuning boxes wipe the floor with a remap is my experience and on 7 diesels I've had. Tuning boxes, the good proper ones, are simple to fit. Cost a fraction too. Can also be disconnected within 2 minutes. No remap can from start to finish.  As for pipercross. Great on Minis of old and not much else. K&N are ultra reputable. Tried tested and adored.

100% disagree, sorry

To answer the initial question, there is already a cold air feed, which makes use of the ram-air effect, built into the grill on the Mk2 Focus.  Anything you do to 'improve' it is likely to make it worse in the real world.

A good re map could make a world of difference, diesels respond really well to a re map. 

I've got a ramair on mines and it makes a very nice noise not quite as nice as petrol but better than some.

16 hours ago, DaveT70 said:

100% disagree, sorry

Shame you couldn't answer my query on your experience Dave.

It's strange how the OP hasn't been back to his thread. How you getting on Adam?

3 hours ago, tazzman600 said:

It's strange how the OP hasn't been back to his thread. How you getting on Adam?

Oh yes he has 🤣

Came back and read the replies yesterday (Monday) at 8:48AM

On 9/26/2023 at 6:04 AM, tazzman600 said:

Shame you couldn't answer my query on your experience Dave.

Tuning boxes are just a resister to trick the fuel rail into giving full pressure all the time, hence the increase in throttle response, but once you get to the point where you would need full pressure anyway, they are doing no more and vehicle is back to standard. You can only increase the fuel pressure to the maximum the pump can pressurise at.

No matter what their name or price, they all do the same thing

A remap will change the fuel pressures as well as the fuel timing and turbo boost amount

K&Ns are renowned for coating the MAF sensor in it's excessive oil, causing running issues 

Tuning boxes don't get much of a mention these days and it's hard to find an independent review of tuning box vs remap. Back in the days when I had VW Group diesels the now defunct Volkswagen Driver and Audi Driver magazines used to do some pretty good reviews.

Also there are what are usually known as "pedal boxes" which act pretty much like using sport mode by altering the map so you get full throttle earlier, but as Dave says, no increase in power overall.

Some of the tuning boxes were complete rubbish (placebos in effect), but I do recall some came out of reviews pretty well and operated in effect like a supplementary ECU.

Fwiw DTUKs offering for the 1.8 TDCI claims about 25bhp increase for £399 which really is no advantage over a Superchips, etc, remap, other than the easy fitting/removal aspect.

https://www.diesel-performance.co.uk/tuning/car/ford/focus-ii-from-2004-to-2012/1-8-tdci-115ps85kw-1753-ccm-3/#go

 

Thanks Dave for finally answering. And oh yes there's been a high percentage of the tuning boxes which were just a resister. Oh yes. But there was a small percentage that the box had a proper circuit board with resistors capacitors and computer chips. It's those I used with great effect. 

And I remember in this forum some 8 or so years back there were a few threads where the merits of tuning boxes were argued lol. There was one ally who provided proof that the one he used (can't remember what it was) on his diesel focus the performance gains and torque was brilliant. 

42 minutes ago, tazzman600 said:

There was one ally who provided proof that the one he used (can't remember what it was) on his diesel focus the performance gains and torque was brilliant. 

Yes, low end. As soon as you get to full pressure on the fuel rail, you're back to standard

No Dave. I don't know where you get your info from but I speak from personal experience and from posts made on here some years ago long before you joined this forum. 

No Vlad. You can't increase the fuel rail pressure over it's maximum pressure, you can only raise it higher than what the PCM is telling it to go before maximum pressure.

Once you're at maximum pressure, that's it.

Now, I'm not disputing that a tuning box doesn't affect low/mid range throttle response and torque, because it does.

But it doesn't affect fuel timing or turbo boost pressure like a remap does

I've ran both